How can weather events such as heavy rainfall affect drinking water quality?

Heavy rainfall can have a significant impact on drinking water quality, particularly in how it can increase turbidity and introduce contaminants into water sources. During heavy rains, the runoff from surrounding areas can carry soil, sediments, debris, and various pollutants into rivers, lakes, or reservoirs that serve as sources for drinking water.

This increase in turbidity occurs because the water becomes clouded with particles that are being washed into the supply. High turbidity levels can inhibit the effectiveness of disinfection processes, as the particles may shield pathogens from chemical treatments. Additionally, pollutants such as fertilizers, pesticides, and other harmful substances can also be introduced, further compromising water quality.

Understanding this effect is crucial for water treatment facilities, which must be prepared to adjust their treatment processes in response to changing water quality conditions caused by extreme weather events. Therefore, the choice correctly highlights the potential negative impacts of heavy rainfall on drinking water sources.